Pumice Filter Media

Hello All What is pumice filter media? is it a good alternative for sand/anthracite specifically for seawater filtration in the Red sea area? What are long term considerations to be assessed for selecting pumice over anthracite for gravity or pressurized filtration plants?  In addition to filtering TSS, will it also help in removing other suspended impurities like TEP, algal blooms, organics, color etc. parameters which are generally neglected by designers of pretreatment section of SWRO plants. Thank you for your help!